Eliminator told me that my x dimension is "seven to six" inches. Not sure why I couldn't get an exact number from the guy but that's what they told me. My engine was dynoed before install and I have the sheet so unless the dyno sheet is fraudulent, those are my numbers. Again, I'm at a loss.

cuzinnote, I agree with cloudmaster 450hp will push one of these boats to 80mph. My boat had an estimated 650hp with a whipple side mount supercharger & dart pro 1 heads with emi thunder exhaust with a -2 inch shorty turning a 30p labbed bravo 1 & was clocked at 96mph in a shootout here just before I bought it. The driver was not even full throttle because it chine walked so bad. I am rebuilding this boat with more power, full hydraulic steering & K planes to make it safer. I expect easily over 100mph if it handles correctly. I did a quick measurement just to see & a stock length drive would be 6 inches for the propshaft depth 4 inches with my shorty so you must have an issue somewhere. Being that my boat had the hp you have now if there is any measurements or anything I can help with please feel free to contact me. Randy

Thank you both. I will most likely need to take you up on that Randy. I realize the numbers don't make sense, that's what makes it so frustrating. First thing I'm going to do is swap out my tach so I know it 100% accurate then start working from there.

[ATTACH=CONFIG]502190[/ATTACH][ATTACH=CONFIG]502191[/ATTACH][ATTACH=CONFIG]502192[/ATTACH]With mine being gutted right now it should be easy for me to get any measurements you might need

X dimension would be taken from the bottom of the rear most pad to center line of out drive lower shaft at the prop. IIRC, mine is about 6 5/8". Make sure the shaft is somewhat level as the drive can be tucked under a 90 degree plane of the rear pad.

I measured from the pivot point on the drive to the bottom of the hull under the drain plug, then measured the drive from the pivot point to the prop shaft & did the math. IROCDave our X dimensions very close if your lower is stock length. I would think cuzinotes boat should be able to spin at least a 28p 4blade to the rev limiter if not a 30p. My boat would blow the prop out really bad if there was any obstruction like a stick to interfere with the flow to the prop. If this boat won't rev there has to be an issue with the engine IMO. Cuzinote can you give the build specs on the engine? Randy

If his boat is making the HP he has said it's making then yes, it should spin a 30p prop. My boat with as far as I know stock 415HP Merc 502 EFI Mag hit's the rev limiter with almost zero trim. That would be with 2 - 4 people and several hundred pounds of " other stuff" in it. The prop is a 26P Bravo 1. I don't know if it's been worked over. With this prop and 2 people (almost zero trim) it hit's a consistent 72 mph. A 28p prop should give a couple of MPH but who knows.

How can you tell if the lower is a shorty? There are no casting or part numbers in the IMCO lower unit.

Holy lot of work dude!! I always wondered if the gas tank went under the front seats at all. Looks like it stays right inboard of the seat screws then? Roughly 1/3rd of my front seat screws are stripped out in the floor. And people have just put longer and bigger screws in, now those are stripped too. I always wondered if they were going into the gas tank......... I need to pull the carpet up and fill those holes and redrill. I have a whole roll of the teal carpet, and it looks like the carpet job in this boat is a cinch since most all the edges are covered by upholstery.

IROCDave, I will measure 1 of my stock lowers & 1 of my shortys & post. Cloudmaster, the screws for the seat bases are on the outer side of the stringers & as far as I can tell just go into the fiberglass floor. I am going to pull the whole floor up & I will post pics on my thread hopefully this week the weather looks like it is going to cooperate a little. Randy

IROCDave, my stock lower is 10" from center of prop shaft to where it mounts to upper. Shorty is 8". Cuzinote do you have any updates? New tach? Check timing? Randy